Diffusion Material for jewelry photographs

In your video How to Photography Your Jewelry by Jim Lawson with Lexi Erickson, Jim mentions diffusion material to soften photos of metals and other materials. It is positioned between the lamp and the item. He rolled out some plastic material, and showed he had it on a frame. What is it called? Source? Excellent video, but I need that material. Thanks.

Jim says you want a product called Dura-lar, the matte surface material. He said your best bet is to
try and find it at a local art supply house, where you can buy just what you need... or you can order it here:http://www.grafixarts.com/product/DuraLar-2